Heretofore, a rotor to be used in a rotary machine includes a core and a rotation transmitting member fixed to the core. The core is made of a laminated steel sheet assembly consisting of magnetic (electromagnetic) steel sheets laminated or stacked. The rotation transmitting member is for example a shaft for a rotary electric machine of an inner rotor type.
For appropriately transmitting rotation of the rotation transmitting member to the core, the rotor must be configured such that the core and the rotation transmitting member are surely fixed to each other. To be concrete, it is necessary to prevent the rotation between the magnetic steel sheets constituting the core, the rotation between the core and the shaft about their axis, and the slippage of the core in a laminating direction (the axial direction of the shaft).
A technique for joining components constituting the rotor is for example disclosed in Patent Document 1 in which a rotor is configured such that an end face of a core in a laminating direction is welded to a shaft. Further, Patent Document 2 discloses a rotor configured such that a plurality of magnetic steel sheets are partially bent, and then the inner peripheral surfaces of the steel sheets are welded to join or connect between the steel sheets.